300 SYRPHID^E. 



Genus XXIX. BACCHA. 



BACCHA, Fb.s. a. 200. 6(1805); Fin.; Mg. ; Mq.; Ztt. ; Ct. ; Udn. 

 Syrphus p., Fb. s. i. Musca p., Gml. Baccha p., St. F. et Srv. 



Corpus gracile. Antenna articulo quarto dorsali. Al& areola sub- 

 apicali Integra, lobo axillari indistincto. Abdomen petiolatum. Fe- 

 mora postica gracilia. 



Body slender. Head semicircular; epistoma slightly depressed, 

 with a scapula ; peristoma oblong, narrow, straitened in front. La- 

 brum targe, broad, notched at the tip, with a spine in the middle and a 

 smaller one on each side. Lingua stout, lanceolate. Maxillae short, 

 slender, subulate, as long as the palpi, slightly curved. Palpi clavate, 

 membranous, hairy towards the tips, not half the length of the labrum. 

 Labium short, stout, cylindrical. Antennae 5-jointed, small, approx- 

 imate, porrect, nutant ; first and second joints small ; first cyathifonn ; 

 second much shorter and broader, bordered with stout bristles ; third 

 almost round, somewhat quadrate, compressed ; fourth very minute, 

 seated on the base of the third ; fifth setiforin, stout, rather short, slightly 

 pubescent. Thorax oval. Wings large, with obtuse tips, very finely 

 pubescent, incumbent and parallel in repose ; subapical areolet entire ; 

 axillary lobe indistinct. Alula3 small. Halteres uncovered. Abdomen 

 pubescent, long, very slender; first segment short, thick in front, 

 narrower behind ; second cylindrical, very slender ; third and fourth 

 somewhat widened. Legs very slender; hind femora not enlarged ; 

 hind tarsi hardly dilated. Male. Eyes contiguous. Abdomen obtuse 

 at the tip. Fern. Eyes parted by a narrow linear front. Abdomen 

 acute at the tip. 



The long slender petiolated abdomen is the most apparent dis- 

 tinctive character of this genus. 



1. elongata, Fb.s.i. ii.430. 42 (1781); Gm. ; Fin. ; Mg. ; Mq.; 

 Ztt. ; Lw. sphegina, Mg. tabida, Mg. ; Mq. ; Ct. vitripennis t Mg. 

 Mnea, antennis nigris articulo tertio ferrugineo, scutello pectoreque 

 chalybeis, alls subcinereis, venis transversis fusco-nebulosis, abdomine 

 cupreo, lateribus fulvo-trimaculatis, pedibus fulvis, tarsis posticis fuscis. 

 Long. 4-H ; alar. 7-8 lin. 



jEneous, head covered with hoary bloom excepting a stripe on the 

 crown and a black shining scapula on the epistoma. Antennae black ; 

 third joint ferruginous. Scutellum chalybeous ; under side of the thorax 

 chalybeous, covered with hoary bloom. Wings slightly grey ; transverse 

 veins clouded with brown ; stigma dark brown. Halteres tawny. Ab- 

 domen cupreous, adorned with three pairs of tawny spots ; first pair 

 small, at the base of the third segment ; second pair large, quadrate, 

 partly united, occupying from one-fourth to one-third of the fourth seg- 

 ment from its base ; third pair small, at the base of the fifth segment. 

 Legs tawny; hind tarsi brown. Var. /3. First and second pair of ab- 



